A Morphometric Study of Age-Related Changes in Adult Human Epiglottis Using Quantitative Digital Analysis of Cartilage Calcification

Abstract

The epiglottis plays an important role in deglutition in humans. The present study investigated age-related changes in the epiglottis using macroscopic and microscopic measurements. Epiglottic specimens from 281 Japanese adult cadavers (177 males, 104 females) were obtained. Specimens were divided into three groups according to age: group I: 20–39 years old (32 males, 26 females), group II: 50–69 years old (82 males, 36 females), and group III: 80–98 years old (63 males, 42 females). Width, height, and thickness were measured macroscopically. To evaluate the degree of calcium deposition, the calcium volume in digitalized von Kossa-stained sections was assessed using a quantitative analysis. An elemental analysis of the area detected with von Kossa staining was done using energy-dispersive X-ray fluorescence spectrometer (EDX). Measurements of the thickness and cell density in the superficial and deep layers of epiglottic cartilage were performed in horizontal histological sections. No significant differences in macroscopic width or height were found across the age groups in either sex. A series of three measurements in males was significantly larger than in females (p < 0.05). The volume of the calcium deposit area was greater in males than in females (p < 0.05) and was significantly increased in group III in males (p < 0.05). The lower level of the epiglottic cartilage showed a greater calcium deposit area than the upper level. In the scanning image by line and surface analysis using EDX, the calcium deposit areas detected with von Kossa staining indicated a close association of calcium and phosphorus ions. The mean Ca/P molar ratio in the calcium deposit area was 1.32 ± 0.12. Microscopic cartilage thickness increased significantly with age (p < 0.05), and was greater in males than in females (p < 0.05). Cartilage cell density in the superficial cartilage layer was higher than in the deep layer and was decreased in group III (p < 0.05). Cartilage cell density was lower in males compared to females. Diameter of chondrocytes significantly increased in group III (p < 0.05) and was larger in males than in females in group III (p < 0.05). Epiglottic cartilage exhibited marked sex-related differences and progression of calcification with age. Calcification of epiglottic cartilage in elderly individuals may affect movement patterns in deglutition.

Structure and composition of arytenoid cartilage of the bullfrog (Lithobates catesbeianus) during maturation and aging

“…Cox and Peacock (1977) described a progressive increase in the deposition of elastic fibers in the auricular cartilage of rabbits with age. Similar descriptions were made by Isamu et al (2001) for the auricular cartilage of humans and by Kano et al (2005) for epiglottic cartilage. The deposition of thick fibers with a similar diameter was observed in these cases.…”

“…Studies in the literature have described calcium deposits widely distributed in laryngeal cartilage of mammals after maturity (Kusafuka et al, 2001;Claassen and Werner, 2004;Kano et al, 2005). In contrast to these reports, in the arytenoid cartilage of the bullfrog larynx, small calcium deposits were only detected in the territorial matrix of 1080-day-old animals, despite a reduction in the number of chondrocytes accompanied by a reduction in GAG content and an increase in the deposition and thickness of collagen fibers in the cartilaginous stroma.…”

“…In addition, several authors reported important age-related structural changes in cartilage PGs in this tissue (Mallinger and Stockinger, 1987;Lotz and Loeser, 2012). Degenerative alterations in tracheal, thyroid and epiglottic cartilage have been described in detail in older adults, with focus on the process of calcification in these structures (Kusafuka et al, 2001;Cruz et al, 2003;Kano et al, 2005).…”

Computational analysis of swallowing mechanics underlying impaired epiglottic inversion

“…A Goodman‐Kruskal index of predictive association was performed comparing frequency data of ECS groups with etiology groups to evaluate if a relationship existed between epiglottic inversion and etiology of swallowing impairment. Kano and colleagues documented increased calcification patterns in elderly male cadavers compared to younger groups . To evaluate if sex‐linked age difference are a factor in this study, a two‐way analysis of variance with post hoc Tukey honest significant difference test of age‐sex by ECS component score was performed.…”

Do mask aperture bars of extraglottic airway devices prevent prolapse of epiglottis causing airway obstruction? A randomized crossover trial in anesthetized adult patients

“…Furthermore, the presence of MABs may interfere with endotracheal intubation if it is necessary to pass a tube through the EAD. According to morphometric studies of adult human epiglottis, the width of the epiglottis is ± 27 mm for males and ± 21 mm for females [15]. This contrasts to the width of the aperture of EADs (ie, ± 15 mm) and questions the necessity of the MABs.…”